Headley, who has pleaded guilty to his role in planning the Mumbai terror attacks, had taken his wife and kids on a vacation during which he received several text messages from Mir seeking to know the peak hours at Mumbai train stations.
"In between Headley's fourth and fifth trips to conduct surveillance in India, Headley met with Sajid Mir on multiple occasions.
"During the first meeting with Sajid, which took place in Rawalpindi, Sajid told Headley that the Mumbai attacks would take place in the next few weeks," according to the transcripts of a Headley interrogation by the FBI, which was unsealed this week at the direction of the Chicago court.
Headley met again with Sajid a short time later and was told by the Lashkar commander that the attack was postponed until at least September 2008 because they needed to wait for calmer waters.
According to the transcripts of the FBI questioning of the 26/11 accused, Headley said a few days before Pervez Musharraf resigned as president of Pakistan he took his wife and kids to a mountain range between Muzzafarabad and Lahore for a short vacation.
"While Headley was with his family he received numerous text messages from Sajid regarding the train station in India where Headley had conducted surveillance," it said.
Headley provided the details to Mir.